Small unmanned air vehicles (UAVs), also known as unmanned aerial systems (UASs) or drones, have been used in photography, surveillance, sensing and mapping applications, payload delivery, and many other uses. The use of small UAVs provides capability for tasks that require cameras or payloads to be present in difficult to access or dangerous locations.
Small UAVs are often electric vehicles with flight time that is limited by battery capacity. When the battery is near being depleted, the operator or mission control software must end the task, fly the vehicle to a service location, land, swap or recharge the battery, fly back to location, and then resume the task. This operational cycle is tedious and time-consuming for a human to be involved. Automated launching, landing, and servicing can mitigate these problems.
Moreover, small UAVs, whether fully autonomous or piloted remotely with a human or computer operator, are deployed by the human operator and managed by human operators while not in use. This required human deployment and management is cumbersome, especially when dealing with multiple vehicles simultaneously, and may be prohibitive when dealing with a large number of vehicles. In addition, the deployment and retrieval of small UAVs, including startup placement, battery and fuel management, and mission initiation requires an informed operator to be present. A storage system according to the principles of the instant disclosure can be used to manage and service a, plurality of UAVs to solve these problems.
Existing methods for automated landing of UAVs exist with various disadvantages. Certain landing methods known in the art, such as net-type or vertical wire systems, require a human to disengage the UAV, require a separate launching mechanism, and/or have a high probability of damage. In the case of a passive landing system, existing autonomous UAV landing requires intelligence to be present on the UAV itself to align with a static landing pad and attempt to maintain alignment throughout the landing process. However, due to size, UAVs have limited processing power and sensing capability onboard, making such a landing procedure disadvantageous. In addition, conditions such as high or turbulent winds, a dynamic moving vehicle, and the like, may cause a failure to maintain alignment and failure to land precisely.
Currently, limited sensing capability on small UAVs requires operators to manually land and launch small UAVs, because of uncertainty to the autonomous vehicle about landing conditions. Ground slope, tail grass, water, and windy conditions create hazards and uncertainty that could cause UAV damage. Software algorithms exist to land UAVs automatically by slowly reducing altitude in small increments until a hard stop is detected, if the operator selects a suitable landing zone beforehand. This is not ideal because flight time is limited, the operator must think about and select a landing location, and the UAV still has to be handled by an operator after it has landed. If the operator wants to hold a position or fly an autonomous mission, the UAV is typically manually launched and then switched into the computer-controlled mode.